Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

826
FXUS63 KLOT 200707
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
207 AM CDT Fri Mar 20 2026

.KEY MESSAGES...

- Spring-like temperatures through the weekend, though Lake
  Michigan will moderate temperatures along the shoreline.

- Cooler temperatures are expected early next week after a cold
  front passes on Sunday.

&&

.DISCUSSION...
Issued at 207 AM CDT Fri Mar 20 2026

An anomalously strong upper-level ridge over the southwest
CONUS will gradually deamplify while shifting across the central
CONUS through the weekend. During this time, a pair of sheared
waves originating from the Pacific Northwest will cross the
Great Lakes region.

A shallow lake-enhanced cold front that crossed northern
Illinois Thursday afternoon/evening has since washed out over or
just south of the CWA early this morning. Developing low-level
southwest flow and some diurnal heating ahead of the first wave
will quickly mix out the front across at least the south half of
the CWA, possibly to the I-88 corridor, through early
afternoon. Another cold front associated with the first wave
will then shift SSW across northern Illinois through the
afternoon. Highs across the Chicago metro, especially near the
lake, will hinge significantly on the timing of the frontal
passage. Expectations are that highs will range from near 60
along the Wisconsin state line to the mid 70s toward central
Illinois, with temps quickly falling into the 40s near the lake
and 50s inland mid to late afternoon.

The front will retreat/wash-out amid developing breezy
southwest winds on Saturday ahead of the second wave to the
north. While some morning stratus may linger across northern
Illinois in the morning, modest WAA will push temps back into
the mid 60s north to mid 70s south.

The cold front tied to the second wave is expected to cross the
area from north to south Sunday morning into early afternoon. A
relatively dry airmass ahead of the front as well as strong low
and mid-level capping suggests a dry frontal passage. A band of
anafrontal precip with perhaps an embedded elevated
thunderstorm is possible late Saturday morning through the
afternoon amid temps falling into the 40s.

Broader WNW flow across the northern CONUS will take hold
across much of next week, with a continued series of waves
crossing somewhere across the Great Lakes region. Cooler but
seasonable conditions will prevail as high pressure passes north
of the area Monday and Tuesday. However, a compact wave removed
from the stronger WNW flow aloft is progged to pass just
southwest of the area on Tuesday and may brush the area with a
few showers. Dry conditions and warming temperatures are favored
Wednesday and Thursday ahead of a stronger trough passing north
of the area.

Kluber

&&

.AVIATION /06Z TAFS THROUGH 12Z SATURDAY/...
Issued at 1222 AM CDT Fri Mar 20 2026

A cold front will move across the terminals this morning
resulting in a wind shift to northwest. In the wake of the front
look for winds to pick up to 10-15kt with a few gusts to around
20 kt possible late this morning into the afternoon. Lake breeze
is expected to develop and flip winds to northeast at GYY first
early-mid afternoon, then likely through MDW later in the
afternoon and eventually ORD by late afternoon/early evening.

VFR conditions are expected through the TAF cycle.

- Izzi

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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